The present invention relates to a text processing system having the feature of automatically printing a prerecorded text according to format control information predefined by the operator.
More particularly, the invention refers to a text processing system having the features of automatically printing lines of text justified with respect to a predetermined length selected by the operator, of automatically centering titles with respect to this selected length and of automatically underlining selected portions of the text.
These features allow the operator to record a draft text without controlling the justification of the text, to enter titles, and to underline portions of the text without backspacing during the recording of the same as is known from prior art machines.
In particular for the underlining feature typewriting machines that are automatically operated by a punch tape on which a text is recorded are known in the art and are disclosed in patents such as U.S. Pat. Ser. No. 2,093,581. In this type of machine, on the same punch tape there are recorded at the beginning and at the end of the next portions to be underlined, two respective underline control codes.
When the machine reads the first control code at the beginning of the portion to be underlined, it stops the escapement of the carriage after the printing of each character and commands the printing of the underlining symbol. After the printing of the underlining symbol, it advances the carriage one character step. When the machine reads the second underlining control code at the end of the portion to be underlined, it resumes the usual control of the carriage escapement.
Clearly this machine has the disadvantage of requiring a special device for controlling the escapement of the carriage during the underlining operation.
The main disadvantage of this machine is however its very slow printing speed due to the particular method of underlining used. In fact, this method requires that at the portion to be underlined, the carriage is stopped for a time sufficient to print a character and an underline symbol in the same position through two consecutive steps. This method cannot be used in the text processing system using a high speed output printer.
A typewriting system with a word underscore control in which the operator records on the text on a magnetic card is known in the art and is described in U.S. Pat. Ser. No. 3,630,336. In this system when it is desired to underline a word, the operator firstly enters the word to be underlined and then records an underlining symbol.
During the automatic printing operation, the symbol is recognized after the printing of the word and causes the printing unit to backspace to the beginning of the word. After this, the printing unit underlines each character of the word and then it resumes the normal printing mode until the next underlining symbol is recognized. Clearly this system has the disadvantage of permitting the automatic underlining of only single words at a time and never groups of words, such as phrases, in one operation.
In fact, to underline a phrase the operator must insert the underlining symbol at the end of each word of it. Moreover, this system does not permit the underlining of spaces between two words to be underlined.